Seal for two-part mercury tube switch envelope



J. H. STALEY June 23, 1936.

SEAL FOR TWO-PART MERCURY TUBE SWITCH ENVELOPE Filed Feb. 15, 1936 Invenzicv; Joseph H. Sta/6g. 54/

Attorneys.

Patented June 23, 1936 PATENT OFFICE SEAL FOR TWO-PART MERCURY TUBE SWITCH ENVELOPE Joseph H. Staley, Columbus, Ind. Application February 13, 1936, Serial No. 63,748

18 Claims.

This invention relates to the art of mercury tube switches and particularly to means for effectively sealing a two-part metallic wall comprising the switch envelope. It has been found to be highly desirable to maintain an. inert gas under pressure within the switch envelope as a means for aiding in reducing the arcing propensities of the switch. Several gases are indicated for the purpose, although hydrogen is commonly employed for the reason that it may be readily secured in practically a pure state. Diificulty has been found in retaining the gas, particularly hydrogen under pressure within an envelope and also in preventing the entrance into the envelope of atmospheric gases, particularly oxygen, but in the present invention herein shown and described in one particular form, a very effective seal is provided.

Reference is made to the accompanying drawing, in which Fig. 1 is a side elevation of one particular form of switch to which my invention may be applied; Fig. 2, a central longitudinal section on the line 2-2 in Fig. 1 discloses the invention;

Fig. 3, a view in perspective of the various eleplied, I provide a tubular metallic body IIJ having a nozzle II of reduced external diameter as compared to the external diameter of the main portion of the body III. I also provide a tubular metallic cap I2 having an internal diameter extending for a major length though exceeding that of the external diameter of the nozzle II.

Circumferentially around the nozzle II is formed a groove I3 spaced inwardly somewhat from the outer end of the nozzle. An insulating collar I4 is slipped over the end of the nozzle II and carried back into abutment with a shoulder formed around the body at the inner end of the nozzle. The outer end of this collar I4 terminates to extend slightly over the inner edge of the notch I3 so as to in effect provide an overhanging lip thereover. A resilient material, here shown in the form of a band I5, is placed over the outer end of the nozzle II around the annular groove I3, the band I5 being of proper dimensions so as to cause it to extend outwardly initially from the groove I3 about the end of the collar I4.

A second insulating collar I6 is slipped by its inner end over the nozzle II into abutment with the band I5 and a cylindrical. arc resisting member I1 is slipped inside of the collar I 6 into abutment with the outer end of the nomle II. The

cap I2 is then carried over the collar I6 in telescoping arrangement and on over the collar I4 confining the band I5 within the cap I2 and between the opposing ends of the collars I4 and I6 and the groove I3 to carry the inner end of the collar I6 back to overhang the groove I3. A shoulder I8 is provided within the cap I2 around the end of the portion thereof which telescopes over the collar I6 so as to provide an annular abutment bearing against the outer end of the 10 collar I6 as the cap I2 is passed thereover.

The relative diameters of the various telescoping members are made to be such that as the cap I2 is forced in place as above indicated, the member I! is firmly gripped within the collar I6 and also the collars I4 and I6 are compressively gripped and urged into sealing contact with the nozzle II and the internal wall of the cap I2. The cap I2 is telescoped sufliciently to carry the collar I6 against the band I5 to cause it to flow and completely fill the groove I3 and also the entire space between the opposing ends of the collars I4 and I6 and out into compressive contact with the wall of the cap I 2. In fact the band I5 is so subjected to pressure that it will flow around and out against the parts of the collars I4 and I6 which overhang the groove I3 so as to urge those overhanging parts outwardly both into compressive contact with the wall of the cap I2. The frictional engagement between the various members is sufiicient to retain the cap I2 in its fully telescoped position as above indicated. In this position, however, the inner end of the cap I2 is spaced a distance from the shoulder of the body II] which forms the abutment for the inner end of the collar I4 so that the cap I2 is not brought into contact with the body III, but is maintained in an insulated relation therewith.

As an additional securing factor, a groove 20 is formed around the inside wall of the cap I2 to be at the same distance from the end of the nozzle II as is the groove I3 when the cap is in its final position, so that the material of the band I5 may likewise flow into and completely fill that groove 20 behind the overhanging ends or lips of the collars I4 and I6.

The body I0 and cap I2 are made out of any suitable metal which will not amalgamate with or contaminate the mercury I9 carried within 50 the envelope formed as above indicated. Iron is one suitable material for these two members, it being understood, of course, that the invention in this particular application does not reside in the materials per se, but in the sealing structure. The member I! .is preferably made of some ceramic material which will resist the deteriorating efiects of an electrical arc and, as indicated and as is shown in.Fig. 2, this member I1 is carried circumferentially by the collar I6 which 60 serves as a resilient mounting for the member. The exact conformation of the member ll does not enter into the invention in this case. Both of the collars l4 and I6 are preferably made out of a resilient or slightly resilient material, one particular material suitable for the purpose being a vulcanized or synthetic resinous fiber. The band [5 should be made out of any material which will cold flow if of the nature of rubber, or be plastic and remain resilient and elastic when so .confined as above indicated throughout the life of the switch. Vulcanized rubber of a good grade is suitable. India rubber serves well. Synthetic rubber preparations are also usable. The band I5 may be formed of some cementing liquid which will set in part or in whole.

In any event, any material is indicated to be usable as the final band I5 which will maintain or exert a pressure over a long period of time between the cap, the nozzle and the ends of the collars protruding, in effect, into the material, or in other words, will not shrink from a sealing contact between those elements. Of course, it is conceivable and within the province of the invention, to rely upon the resilience of the protruding ends of the collars l4 and It to maintain the band material under sealing pressure although it be of a nature having slight or no compressibility.

While I have herein shown and described my invention in the one particular form, it is obvious that structural variations may be employed without departing from the spirit of the invention and I, therefore, do not desire to be limited beyond the limitations as may be imposed by the following claims.

I claim:

1. A seal between outer and inner telescoping members comprising a pair of spaced apart resilient members interposed under stress between the said outer and inner members, and sealing means between and about opposing ends of said resilient members.

2. A seal between outer and inner telescoping members comprising a pair of spaced apart resilient members interposed under stress between the said outer and inner members, and sealing means between and about opposing ends of said resilient members, said outer member urging one of said resilient members toward the other and frictionally engaging about the other of said resilient members to efiect and maintain pressure on said sealing means.

3. A seal between outer and inner telescoping members comprising a pair of spaced apart resilient members interposed under stress between the said outer and inner members, and sealing means between and about opposing ends of said resilient members, said outer member urging one of said resilient members toward the other and frictionally engaging about the other of said resilient members to effect and maintain pressure on said sealing means, each of said telescoping members having shoulders abutting and maintaining said resilient members in relatively fixed positions.

4. A seal between outer and inner telescoping members comprising a pair of resilient members spaced end to end and interposed under stress between said telescoping members, one of said telescoping members having a groove at the opposing ends of the resilient members, and means flowable under stress between said ends filling said groove and sealably maintaining said ends in compressive contact with the other of said telescoping members, the outer of said telescoping members being carried over one of said resilient members and into frictional engagement about the other resilient member to efiect said stress on said flowable means.

5. A seal between outer and inner telescoping members comprising a pair of resilient members spaced end to end and interposed under stress between said telescoping members, one of said telescoping members having a groove at the opposing ends of the resilient members, and means flowable under stressbetween said ends filling said groove and sealably maintaining said ends in compressive contact with the other of said telescoping members, the outer of said telescoping members being carried over one of said resilient members and into frictional engagement about the other resilient member to eifect said stress on said flowable means, said opposing ends of the resilient member overhanging said groove.

6. In a mercury tube switch, an envelope in two parts, a resilient bushing fitted over one of said parts, a second resilient bushing also fitted over said one part with one end opposing the first bushing and its other end extended beyond said part, an arc resisting member fitted .within the extending portion of the second bushing, the

other of said envelope parts being fitted comparts, a second resilient bushing also fitted over said one part with one end opposing the first bushing and its other end extended beyond said part, an arc resisting member fitted within the extending portion of the second bushing, the other of said envelope parts being fitted compressively over the second bushing across onto and compressively, engaging the first bushing, and sealing means between the two envelope parts and the opposing ends of the resilient members, said other envelope part having a shoulder abutting the outer end of said second resilient member extending portion, and said second envelope part having a shoulder abutting the outer end of said first resilient member, whereby said means may be subjected to pressure by further telescoping of said envelope parts.

8. In a mercury tube switch, an envelope in two parts, a resilient bushing fitted over one of said parts, a second resilient bushing also fitted over said one part with one end opposing the first bushing and its other end extended beyond said part, an arc resisting member fitted within the extending portion of the second bushing, the other of said envelope parts being fitted compressively over the second bushing across onto and compressively engaging the first bushing, and sealing means between the two envelope parts and the opposing ends of the resilient members, said other envelope part having a shoulder abutting. the outer end of said second resilient member extending portion, and said second envelope said one part with one end opposin the first 75 bushing and its other end extended beyond said part, an arc resisting member fitted within the extending portion of the second bushing, the

other of said envelope parts being fitted compressively over the second bushing across onto and compressively engaging the first bushing, and sealing means between the two envelope parts and the opposing ends of the resilient members, said one envelope part having a groove between the opposing ends of said bushings, and said sealing means filling said groove.

10. In a mercury tube switch, an envelope in two parts, a resilient bushing fitted over one of said parts, a second resilient bushing also fitted over said one part with one end opposing the first bushing and its other end extended beyond said part, an arc resisting member fitted within the extending portion of the second bushing, the

other of said envelope parts being fitted compressively over the second bushing across onto and compressively engaging the first bushing, and sealing means between the two envelope parts and the opposing ends of the resilient members, said one envelope part having a groove between the opposing ends of said bushings, and said sealing means filling said groove, said opposing bushing ends overhanging said groove whereby said sealing means may ,fiow under said ends.

11. In a mercury tube switch, an envelope in two partsya resilient bushing fitted over one of said parts, a second resilient bushing also fitted over said one part with one end opposing the first bushing and its other end extended beyond said part, an arc resisting member fitted within the extending portion of the second bushing, the other of said envelope parts being fitted com-- pressively over the second bushing across onto and compressively engaging the first bushing, and sealing means between the two envelope parts and the opposing ends of the resilient members, said one envelope part having a groove between the opposing ends of said bushings, and said sealing means filling said groove, said opposing bushing ends overhanging said groove whereby said sealing means may fiow under said ends, said two envelope parts being sufiiciently telescoped to subject said sealing means to stress, forcing said means in said groove laterally against said overhanging ends and carrying said ends into sealing contact with one of the envelope parts.

12. In a mercury tube switch, a metallic envelope comprising a body and a cap, a resilient insulating collar fitted around the body, a second resilient insulating collar fitted around the body adjacent the first collar, sealing means around the body between adjacent ends of the two collars, said cap compressively fitting over the second collar and onto the first collar to lap over the opposing collar ends and said sealing means, said collars insulating the cap from and sealably connecting the cap with the body.

13. In a mercury tube switch, a metallic envelope comprising a body and a cap, a resilient insulating collar fitted around the body, a second resilient insulating collar fitted around the body adjacent the first collar, sealing means around the body between adjacent ends of the two collars, said cap compressively fitting over the second collar and onto the firstcollar to lap over the opposing collar ends and said sealing means, said collars insulating the cap from and sealably connecting the cap with the body, a shoulder on the body positioning the first collar, and a shoulder in the cap positioning the second collar.

14. In a mercury tube switch, a metallic envelope comprising a body and a cap, a resilient insulating collar fitted around the body, a second resilient insulating collar fitted around the body adjacent the first collar, sealing means around the body between adjacent ends of the two collars, said cap compressively fitting over the second collar and onto the first collar to lap over the opposing collar ends and said sealing means, said collars insulating the cap from and sealably connecting the cap with the body, said body having an annular groove located between the opposing ends of the two collars, said sealing means being located by and entering and filling said groove.

, velope comprising a body and a cap, a resilient insulating collar fitted around the body, a secondresiliently insulating collar fitted around the body adjacent the first collar, sealing means around the body between adjacent ends of the two collars, said cap compressively fitting over the second collar and onto the first collar to lap over the opposing collar ends and said sealing means, said collars insulating the cap from and sealably connecting the cap with the body, said body having an annular groove located between the opposing ends of the two collars, said sealing means being located by and entering and filling said groove, said groove being continued under each of the said opposing collar ends to carry said sealing means thereunder.

16. A seal between outer and inner telescoping members comprising a pair of resilient members spaced end to end and interposed under stress between said telescoping members, one of said telescoping members having a groove at the opposing ends of the resilient members, and means fiowable under stress between said ends filling said groove and sealably maintaining said ends in compressive contact with the other of said telescoping members, the outer of said telescoping members being carried over one of said resilient members and into frictional engagement about the other resilient member to effect said stress on said fiowable means, the other of said telescoping members having a companion groove positioned to receive said sealing means, whereby said sealing means extends by said grooves below the opposing faces of the telescoping members to form an interlock therebetween.

17. A seal between outer and inner telescoping members comprising a pair of spaced apart resilient members interposed under stress between the said outer and inner members, and sealing means between and about opposing ends of said resilient members, said telescoping members each having means engaged by said sealing means to interlock the telescoping members.

18. A seal between outer and inner telescoping members comprising a pair of spaced apart members interposed under stress between the said telescoping members, and sealing means between and about opposing ends of the said spaced members, at least one of said telescoping members having means interlocking with said sealing means.

JOSEPH H. STALEY. 

